After treatment of central nervous system (CNS) tumors, neuroendocrine dysfunction is common. We will investigate the hormonal mechanisms underlying the effects of cranial and craniospinal radiation on linear and segmental growth, adolescent development and body composition in childhood survivors of CNS tumors. We will investigate the timing and tempo of these endocrine alterations in relation to time of radiation by evaluating these children every 6 months for 2 years. This is a longitudinal study and although patients are being admitted, the data are not fully analyzed. Preliminary analyses does not show deviations from expected growth.